1,6,7,8 - Series and Mini CooperGeneral Chat related to models that do not fit into particular categories above. Please try to put your discussion in more appropriate sections. This section does cover the 1 Series, MINI Cooper and 8-Series vehicles: BMW 830i, BMW 840Ci, BMW 850i, BMW 850Ci, BMW 850CSi, M8, Alpina B12, BMW CS Concept and others.
My wife's 01 740il, 135K, has for the last 6 months been developing a (what I incorrectly called a surge) that was barely noticeable at light throttle, highway speeds. As I have watched, the tach when it drops engine speed to engage overdrive, the engine makes a growling or "snoring" sound and pops out of overdrive. Took it to a local bimmer shop (not dealer). Said the Vanus valve was bad from sludge (Thanks BMW service plan from original owner). Caused the control module mounted in conjunction with themostat housing to go bad because the vanus could not move properly confusing the module and burned it out. (not sure I buy it) Anyways, this growling, gear hunting, transmision chattering occurance happens ONLY after the car has achieved operating temp. I have taken the throttle body apart, no wear detectable. Have replaced the spark plugs and boots. HAve spent 1600 dollars on shop to replace vanus valve, control module, etc, Now problem is worse. And the check engine light does not come on (bulb burned out now) It should come on, I unplugged the RH cam timing sensor to check the functional change in the shifting. None. Please, any help would be appreciated. Don't have money for shop again and Wife won't drive it.
Last edited by DACollins; 12-15-2008 at 06:43 PM.
I would go for the PCV valve which is at the rear of the intake manifold no.2 in the picture, however comes as a complete unit now, so the part no. may have changed and only ava at BM dealer, so just take the pic along with you, it is a DIY put is fiddly and required hex/star sockets and an osteopath when youv'e finished for your back!!!
This is my guess what it is, but I cant guarantee it, they basiclly are a bellow and over time the bellow gets brittle and falls apart.
You may also want to consider this option 1st, which is from a friend on another forum I belong too. after what he did in the link below, he also changed the PCV as it still wasnt quite right, but now runs like a dream!!
That BMW case study information makes perfect sense to me. At around 135 or 140K now, I think it would make sense to change the trans. fluid and filter.
I have heard that changing the fluid is complex and not for the do it yourselfer. Although I heard this from the mech. that changed the vanos valve for me. We did discuss the trans. service and he recommended BMW trans. fluid. Is this the recommended fluid? Could I use Mobil1 or (my preference) Kendal Synth.? Where could I go to find the proceedures? I don't mind technical stuff, just need some input. Thanks for all your help!!
MERRY CHRISTMAS to ALL!!
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